Construction of reversible hydration–dehydration system by a model compound and a novel polymer bearing vicinal tricarbonyl structure

Abstract

A novel polymer bearing acyclic vicinal tricarbonyl moieties in the side chains was synthesized by (1) radical polymerization of a styrene derivative with a 1,3-diketone structure and (2) successive treatment of the resulting polystyrene derivative by N-bromosuccinimide to convert its 1,3-diketone moiety in the side chains into the corresponding vicinal tricarbonyl moiety. The tricarbonyl moiety was highly reactive with water to permit its rapid conversion into a geminal diol structure in water-containing acetone. On the other hand, heating the resulting polymer bearing the geminal diol structure under vacuum enabled successful recovery of the vicinal tricarbonyl moiety to demonstrate the reversible nature of this system, which allowed us to repeat the hydration-dehydration cycle without deteriorating the polymer structure.

Reversible crosslinking and decrosslinking of polymers containing alcohol moiety using an acyclic bifunctional vicinal triketone

“…S4). The weight loss of 6 below the T d5 and T d10 was mainly attributable to the decomposition of the thermally labile hemiketal group, which lowered those temperatures. On the other hand, the thermally stable aromatic rings originating from the bistriketone crosslinker could explain the increase in T d15 .…”

“…Furthermore, these addition–elimination behaviors are detectable by the naked eye, as they are accompanied by collapse and recovery of the three sequential carbonyl groups characterized by yellow–orange coloration. Intrigued by these characteristic features, we have designed and synthesized polystyrenes bearing tricarbonyl and its hydrate structures . We carried out crosslinking of the polystyrenes through hemiketal linkages by using α,ω‐diols, and the crosslinked polymer could be decrosslinked by treatment with water‐containing solvents to give the original polystyrenes in high yields .…”

Synthesis of polymers containing vicinal tricarbonyl moiety and construction of reversible crosslinking–decrosslinking polymer system

“…DPPT reacts with water efficiently at ambient temperature not only in moisturized solutions but also in moisturized air 14 . DPPT is a yellow powder and its solution exhibits a distinctive orange color, and thus the progress of its hydration can be monitored based on the color intensity.…”

“…The electron‐withdrawing nature of the carbonyl groups enhances their electrophilicity, particularly that of the center group 13 . The high electrophilicity of the center carbonyl group allows it to react with various nucleophilic compounds such as water, 14 alcohols, 15 thiols 16 and anilines, 17 providing the corresponding geminal diols, hemiacetals, hemithioacetals and hemiaminals, respectively. Typical reactions of 1,3‐diphenylpropanetrione (DPPT) are shown in Fig.…”

Degradable high Tg sugar-derived polycarbonates from isosorbide and dihydroxyacetone

“…Endo and co-workers have reported radical differences in the solubility of polystyrene with pendant tri-carbonyls upon the formation of its hydrate form. 31 The alternating analogue (VII-d) consists of one type of carbonate linkage, namely from DHA to isosorbide, with a more limited conformational mobility compared to its blocky random counterpart (V-d). The alternating analogue should thus be less prone to an intramolecular nucleophilic attack, given that each DHA-unit is anchored to the more rigid isosorbide.…”